Brake drum assembly



March 26, 1935.

c. R. STOUGH ET AL 1,995,691

BRAKE DRUM AS SEMBLY Fil ed April 15, 1952 4 Sheets-Sheet 1 I 1 II I IIINVENTOR5 CharIes/QSfouy/v and Fran/r W Schmidt BY I THE/ R ATTORNEY.

March 26, 1935. Q R, STOUGH ET 1,995,691

BRAKE DRUM AS SEMBLY Filed April 15, 1952 4 Sheets-Sheet 3 a9 QI'Q/THEIR ATTORNEY.

March 26, 1935. c s ou ET AL v 1,995,691

BRAKE DRUM AS SEMBLY Filed April 15, 1932 4 sheets-sheet 4 INVENTORChar/c5 1P. Sway/7 and Fra/YAW. Sz/vm/df.

7 H E] R ATTORNEY.

The splashing or throwing of water, mud*or gravel by the wheels, runningboard and fenders seal the braking surface of the brake drum from theprovision of a flexible seal for brake drums.

Patented" Man 26, i935 I 1 ,UNITED STATES PATENT OFFICE BRAKE DRUMASSEMBLY Charles R. Stough and Frank W. Schmidt, Lansing, Mich,assignors to Motor Wheel Corporation, Lansing, Mich.,'a' corporation ofMichigan Application April 15, 1932, Serial s... 605.438 6 Claims. (Cl.wa -21s) This invention relates to brake drum assemblies and moreparticularly to brake drum assemblies of the so-called internalexpanding type.

secured to an annular flange 14 formed integrally with the hub 15 bymeans of an annular bracketmember 16 connected to the hub shell 12 bythe rivets 17 and to the annular hub flange 14 by means of stud bolts18. The hub 15 is provided with a plurality of bearing members 19 withinwhich is supported a conventional vehicle wheel axle member 20. A hubcap 9 may be used to close the open end of the-hub shell 12. A brakedrum 21 comprising an annular brake ring 22 provided with a suitablebraking material 23 on its inner surface and a brake web 24 secured tothe brake band 22 in any suitable manner as by welding, is secured tothe anof an automobile into contact with the braking surface of thebrake drum assemblies associated therewith shortens the life andfrequently causes unsatisfactory operation of brake drum assemblies. 'Inthebrake' drums in use heretofore the only means relied. upon forpreventing foreign substances. from coming in contact with the brakingsurface has been a conventional backing plate positioned tosubstantially close the open face of the brake drum and provided with aperipheral flange spaced from and encircling the open edge of the brakedrum. Due to the different angles from which water, mud and simi-' larforeign substances are splashed or thrown by the various parts of theautomobile, the conven tional backing plate is inadequate to completely25 and thestud bolts 1 8. ,A'backing plate 26 is secured to the innerextremity of the axle member 20 against an enlarged shoulder 27 formedthereon. An annular baflle or seal 28 is secured to the backing plate 26whereby to substantially close the opening between the inner extremityof the hub 15 and the backing plate. The backing plate 26 substantiallyclosesthe open face'of the brake drum 21 and has a peripheral flange 29disposed in spaced concentric relation to one edge of the brake band 22.The backing plate is provided with suitable openings 30 through whichextends mechanism for operating the brake shoe, not shown.

It will be observed that the peripheral fla 29 of the backing plate 30overhangs the edge of the brake band 22 in-such manner as to preventforeign substances of any kind entering within thebrake band directlybut does not prevent such suchforeign substances.

Accordingly, the principal object of the pre ent invention is theprovision of novel means adapted to prevent foreign substancesfromcomving in contact with the braking surface of the brake drum.Another object of the invention is A further object is the provision ofa removable seal for brake drum assemblies. Other objects more or lessancillary .to the foregoing will appear inthe following description andclaims.

For a-better understanding of the invention reference may now be had tothe accompanying drawings, in which: r

Fig. I is a cross sectional view of a conventional wheel and brake drumassembly;

Figs. II to VII inclusive arepartial sectional views through brake drumassemblies including as an element thereof flexible sealing means, someof which are removable;

Figs. VIII to XVI inclusive are partial sectional views of brake drumassemblies including as an element thereof metallicor rigid sealingmeans, deterioration of the'braking surface. some of which areremovable; and A sealed ring 33 formed of suitable flexible wear Fig.XVII is a partial cross sectional view of flesisting fibrous material;is positioned between a brake drum assembly embodying a combine.- theperipheral flange 29 and the edge of the' brake tion metallic andflexible seal; and ring 22. This ring serves to prevent water and Fig.XVIII is a partial cross sectional view of other foreign substances fromentering the brake a brake 'drum assembly embodying a seal somedrum andinterferingwith the operation thereof. what similarto that showninFig'.'IX. The seal is secured in position by means of a The vehiclewheel 10 shown in Fig. I comprises a rim 11 secured to a hub shell 12 bymeans of firmly against the inner surface of the flange a plurality ofspokes 13. The hub shell 12 is 29. The seal is positioned sothat theinner edge brake band'22 and the'fiange 29 when movingin a directionaway from the wheel and toward the backing plate 30; Consequently, theconventional. backing plate 26 shown in Fig. I serves to only partiallyprevent foreign substances from enterbraking surface 23 and the brakeshoe, not shown, whereby to prevent the satisfactory operation ofthebrake assembly andto cause the premature nular flange 14 of the hub15 by means of rivets.

substances from passin between the edge of the resilient wire ring 36which presses the same 40- ing the brake drum 21 and lodging between thethereof engages the edge of the brake ring 22. It is formed withsuflicient rigidity to maintain contact with the edge of the ring 22. Asthe brake ring rotates the edge thereof rotates against the seal 33 thusmaintaining an effective closure at all times between the stationarybacking plate 26 and the rotating brake drum 21.

The various modified forms of seals shown in Figs. II to XVII inclusiveare designed to provide a substantially perfect seal against theadmission of foreign substances to the interior of the brake drumassembly with which they are associated. Each of the structures shown inFigs. 11 to XIII inclusive and XVI to XVII includes a backing plate 26,a brake ring 22 having a braking surface 23 secured thereto and a brakedrum web 24 secured to the brake ring 22 by welding or other suitablemeans. The structure shown in Figs. XIV and XV includes a backing plate26, a cast metal brake ring 31, and a brake drum web 24 welded to thebrake ring 31 at 32.

The seal forming a part of the brake drum assembly illustrated in Fig.II consists of an annular fibrous ring 33 folded upon itself andpositioned between the curved peripheral flange 34 of the backing plate26 and the adjacent edge of the brake ring 22. The flbrous ring 33,which may be of any suitable flexible wear-resisting material such asleather or the like, is secured to the external surface of the brakering 22 by being stretched over the edge thereof. As the brake drumrotates the fibrous ring 33 will usually rotate with the ring 22 andslide against the inner surface of the peripheral flange 34. In thismanner water as well as other foreign substances is prevented fromentering within the brake band 22.

The seal shown in Fig. In is substantially identical to the seal shownin Fig. II except that it is secured to the flange portion 35 of thebacking plate 26 by means of a flexible wire ring 36 which presses theflexible fibrous seal 33 against the corrugated portion of the backingplate 26. The peripheral portion of the backing plate 26 is also flangedas indicated at 37 whereby it overhangs the outer extremity of the ring22. The flexible fibrous seal 33 slides against the outer edge of thebraking surface 23. Accordingly any water or other foreign substancewhich enters between the peripheral flange 37 and the outer extremity ofthe ring 22 is prevented from coming in contact with the braking surface23 by the seal 33.

The structure shown in Fig. IV is substantially the same as the brakedrumassembly shown in Fig. I except that the fibrous seal 33 ispreferably secured in position by being vulcanized to the flange 37. Inthe assembly shown in Fig. IV the seal 33 is preferably made of fibrousmaterial sufliciently rigid to permit it to be molded to the desiredshape whereby the free extremity thereof is held against the outer edgeof the brake ring 22 and its braking surface 23 whereby to prevent allforeign substances from entering within the brake drum.

The assembly shown in Fig. V is identical to that shown in Fig. IV withthe exception that the fibrous seal 33 is of slightly different design.In this case the seal is pre-molded or formed to the contour shownwhereby it is fltted on to the free edge of the peripheral flange 37 ofthe backing plate 26 and held there by its own elasticity and by reasonofthe pressure against its free extremity by. the edge of the brake ring22 and braking surface 23.

foreign substances from entering within the brake drum.

The structure shown in Fig. VII comprises a conventional brake drum andbacking plate assembly with the addition of an annular seal retainingring 38 welded or otherwise secured to the inner surface of the backingplate 26. A fibrous seal 33 in the shape of a ring has one edge thereoffitted into the slot formed by the backing plate 26 and the retainingring 38 and its other extremity contacts the free edge of the brakingsurface 23. Accordingly, any water or other foreign substances whichpass through the opening between the edge of the backing plate flange3'7 and the brake ring 22 is caught by the fibrous seal 33 and due tothe circular formation of the seal and backing plate, passes to thelower side thereof and falls away from the brake drum assembly.

The assemblies shownv in Figs. VIII, x and XI each include a resilientremovable metal seal 39 in the form of a shield secured to the brakering 22 by being pressed or forced into engagement therewith. In each ofthese assemblies the peripheral flange 40 of the backing plate 26prevents foreign substances from entering the opening between thebacking plate and the brake ring 22 from one direction and the seals orshields 39 prevent similar substances from entering the same openingfrom the opposite direction. In other words, each of these assemblies isprovided with a double seal or shield adapted to prevent the admissionof foreign substances to the interior of the brake drum assembly.

In the assembly shown in Fig. IX a metallic shield or seal is welded or'otherwise suitably secured to the outer periphery of the backing plate26 and extends partially over the rib portion 42 of the brake ring 22.Accordingly the rib portion 42 prevents foreign substances from enteringthe opening between the backing plate 26 and the brake ring 22 from onedirection while the shield 41 prevents such substances from entering thesame opening from the opposite direction. This assembly therefore isalso provided with a doubleseal against the admission of foreignsubstances to the interior of the brake drum.

A metallic shield 43 in the form of an annulan ring having an upturnedflange at one edge thereof is secured to the brake ring 22 shown in Fig.XH by welding at 44. The flanged edge of the ring 43 extends beyond theouter'periphery of the backing plate 26 whereby foreign substances ofall kinds are prevented from entering the opening between the backingplate and the brake ring 22. Any water and dirt or similar substanceswhich are thrown against the outer surface of the ring 43 are dischargedtherefrom by reason of the rotary movement of the ring 22 to which thering 43 is attached.

The assembly shown in Fig. XHI embodies substantially the same-idea asthe assembly lust described. In this case, however, the outer edge ofthe brake ring 22 is extended to overhang the outer periphery of thebacking plate 26 and an annular groove 45 is formed in the ring 22adjacent its outer edge to collect and drain of! moisture and similarsubstances.

The assemblies shown in Figs. XIV, XVI and XVII each embody a flangedportion secured to the backing plate 26 which overhangs the edge of thebrake ringand a guard or shield secured to the inner surface of thebacking plate 26 and positioned to prevent foreign substances which havepassed the overhanging flange from enter- 1 ing within the brake drumassembly. As shown in Fig. XIV this is accomplished by securing asubstantially U shaped annular ring 46 to the outer periphery of thebacking plate 26 by welding. One leg of the U shaped ring 46 overhangs.the brake ring 31 and the curved extremity 4'7 ofv the other leg ispositioned within the brake ring 31 in close proximity thereto. In Fig.XVI the; backing plate 26 is provided with .a peripheral the outersurface of the backing plate 26 as by welding and its other edge isdeformed to enclose the outer edge of the brake ring 22. A rubber seal52 preferably in the form of a ring may be inserted between the backingplate and the ring 49 to prevent moisture from lodging between theseparts.

A further modified form of the structure shown in Figs. XIV, XVI andXVII is shown in Fig. XV. In this case the outer edge of the brake ring31 is flanged as indicated at 50 and. the backing plate 26 is disposedwith the body portion thereof within the brake ring 31 and with theflanged periphery 51 thereof. spaced concentrically from the flange 50.An annular ring 52 has one edge secured to the inner surface of thebacking plate 26 and itsother edge disposed in concentric rela- .tion tothe inner surface of the body of the brake ring 31. r I

The structure shown in Figure XVIII is a variation' of the brake drumassembly illustrated in Fig. IX. In this variation-the backing plate 26terminates in a laterally extendingperipheral flange 40 which overliesthe open edge of the ring 22. A metallic shield 53, having one edgeoverlying the flange 40 and the rib 42 formed in the ring 22, is securedto the backing plate 26 by the securing members 54. The shield 53 is anincomplete ring and extends only partially around the periphery of thebacking plate 26. Preferably it is of suitable extent and so positionedas to substantially close the top and front of the brake drum only. Inthis manner all foreign substances which may be thrown toward the brakedrum by the various parts of the vehicle are prevented from enteringwithin the drum, while at the same time the dust resulting from theinternal wear of the friction surfaces within the drum is permitted tofall out of the drum at the under side thereof.

Fromthe foregoing description it will be apparent that this inventionprovides a brake drum assembly embodying an unusually eiflcient sealwhich may be either of flexible or rigid material and which may beremovably attached to the brake drum or backing plate or permanentlysecured .thereto. While only the preferred modifications of theinvention have been shown and described it should be understood that theinvention is not limited thereto but is coextensive with the scope ofthe appended claims.

We claim: Y 1. A brake drum assembly comprising a brake ring, a backingplate disposed in spaced relation to one edge of the ring, a sealpositioned between the edge of the ring and the backing plate whereby toclose the opening therebetween, and ,removable resilient means forfastening the seal to the inner surface of the backing plate. a

2. A brake drum assembly comprising a brake ring, a backing platedisposed in spaced relation to the edge of the ring, a seal positionedto close the opening between the edge of the ring and the backing plate,and a removable resilient ring for pressing the seal against the innersurface of the backing plate whereby to secure the seal thereto.

.3. A brake drum assembly comprising a brake ring, a backing platedisposed in spaced relation to the ring and having a peripheral flangeoverthe opening between the said flange and the edge of the ring, and aremovable resilient ring for pressing the seal against the inner surfaceof said flange whereby to secure the seal thereto.

4. A'brake drum assembly comprising a brake ring, a backing platedisposed in spaced relation to the ring and providedzwith a peripheralchannel partially enclosing an edge of the ring, a seal positioned toclose the opening between the backing plate and the inner surface of thering at one edge thereof, and a removable resilient ring for pressingthe seal against a wall of said channel whereby to secure the sealthereto.

5. A brake drum assembly comprising a brake ring, a backing platedisposed in spaced relation to one edge of the ring, a seal positionedbetween theedge of the ring and the backing plate whereby to close theopening therebetween, and removable means for securing the seal to thebacking plate.

CHARLES R. STOUGH.

